What about

re-search-forward               re-search-forward
re-search-backward              re-search-backward
replace-regexp-in-string        re-replace-in-string
replace-match                   re-replace-match
string-match                    re-search-in-string
match-string                    re-matched-string

This sounds good, but I think `regexp-` is a better namespace given there is `regexp-quote`, `regexp-opt` etc. That'd also probably mean alias `replace-regexp` as `regexp-replace`.